Combination of hydrogen producing and hydrogen consuming units



June 15, 1965 J. B. PoHLl-:Nz ETAL COMBINATION 0F HYDROGEN PRODUCING ANDl l HYDROGEN CONSUMING UNITS Filed Nov. 7, 1960 United States Patent O3,189,538 COMBINATION F HYDROGEN PRODUCING AND HYDROGEN CGNSUMING UNTSJack B. Pohlenz, Arlington Heights, and Donald H. Belden, ProspectHeights, Ill., assiguors to Universal Oil Products Company, Des Plaines,Ill., a corporation of Delaware Filed Nov. 7, 1960, Ser. No. 67,532 3Claims. (Cl. 208-58) This invention relates to an improved combinedsystem of hydrogen producing and hydrogen consuming processes wherein auidized high temperature cracking unit serves as means for purifying ahydrogen stream as well as a hydrogen supply zone.

Commercial production of hydrogen has generally made use of theWater-gas reaction, where carbon and steam are reacted, or alternativelythe shift reaction, where carbon monoxide and steam are reacted.However, in the present improved combined operation no Water or steam isutilized in the hydrogen producing or purification sections. Insteadhydrogen production is elected by conventional hydrocarbon conversionprocessing and by the high temperature uidized contact of subdividedcatalyst particles with a hydrocarbon containing stream to effect theformation of hydrogen and carbon. The hydrocarbon charge may be obtainedfrom one or more hydrogen consuming and/or hydrogen producinghydrocarbon conversion units which are integrated with the fluidizedunit. In the fluidized high temperature cracking operation, ahydrocarbon stream contacts heated sub-divided catalyst particles at asuitable controlled rate and temperature effecting the conversion of amajor portion of the hydrocarbon charge to hydrogen and carbon, suchthat there is a resulting hydrogen rich stream substantially free of anycarbon oxides. This type of hydrogen production is of particularadvantage in that the resulting hydrogen stream is useable as such,Without further treatment in other hydrocarbon conversion systems.

It is a principal object of the present invention to utilize a uidizedhydrogen producing unit in a system of hydrogen producing and hydrogenconsuming conversion units as a source of hydrogen and/ or as a hydrogenstream purifier.

Actually, the fiuidized hydrogen producing unit of the system may serveas a balancing unit in the combination of hydrocarbon conversion units.For example, if in the combination of processing units there is a netdeciency of hydrogen in the processing units, such deficiency may bebalanced by the direct introduction of natural gas, or other hydrocarbonstream, to the fluidized hydrogen producing unit to form hydrogen by thehigh temperature catalytic cracking operation. lf, on the other hand,there is a surplus of hydrogen Within the combination of processingunits, the excess may be Withdrawn at a point downstream from thefluidized hydrogen producing unit, providing thereby a net hydrogenstream which is generally 85%, or higher, in hydrogen content and ofuseable purity for most any chemical or hydrocarbon processingoperation. The major component in the hydrogen rich stream comprisesprimarily unconverted methane, there being little if any contaminationby carbon oxides. Thus, the uidized hydrogen producing unit serveseither as a hydrogen stream purifier, or a combinationpurifier-producer.

Another object of the present invention is to provide a iluidizedhydrogen producer-purifier unit which makes use of a uidized carbonburning zone which is operated to effect the production of a carbonmonoxide rich effluent stream available for use as a reducing gas in areducing unit, or which may be burned to carbon dioxide for the sagessePatented .lune l5, i965 "nce generation of heat which in turn may beused to produce high temperature steam useful in various refinery units.The carbon monoxide rich stream may, of course, be used directly inchemical operations, such as in the manufacture of formic acid or urea,or alternatively, the carbon monoxide may be used with steam in agas-shift reactor to produce additional hydrogen.

In a broad aspect, the present invention provides a combination processfor converting a hydrocarbon stream to produce hydrogen and morevaluable hydrocarbon fractions in a manner comprising, passing ahydrocarbon charge stream to be converted to more valuable productstogether With a hydrogen containing stream, obtained as hereinafter setforth, at an elevated temperature and an elevated pressure to a confinedcatalyst containing hydrogen consuming reaction zone and effecting theconversion of the charge stream to provide an eluent stream containingthe desired improved products, separating therefrom a light normallygaseous stream and passing it to a separate hydrogen supply zone whereinsuch stream contacts sub-divided heated catalyst particles at anelevated temperature and at a rate effecting the cracking of a majorportion of the hydrocarbon content of such gaseous stream into hydrogenand carbon, and passing hydrogen from the hydrogen supply zone to thehydrogen consuming reaction zone to combine with the charge stream asaforesaid.

Various combinations of hydrogen consuming and hydrogen producingconversion units may be used Within the scope of the present inventionwith one or more types of hydrocarbon conversion reactions being carriedout in conversion units at conditions providing a net production ofhydrogen. For example, various hydrocarbon dehydrogenation and reformingoperations effect the net production of hydrogen and in such instances,one or more of such units may provide a primary source of hydrogenuseable for recycle hydrogen as well as a hydrogen source for hydrogenconsuming reaction units, while the uidized high temperature crackingunit may serve as a secondary source of hydrogen or as ahydrogen-producer-'purifier unit.

In a more specific embodiment, the present invention comprises acombination process for converting hydrocarbons to produce hydrogen andmore valuable hydrocarbon fractions, in a manner which comprises,passing a hydrocarbon charge stream together with a stream which isprincipally hydrogen, obtained as hereinafter set forth, at an elevatedtemperature and at an elevated pressure to a confined catalystcontaining hydrogen consuming reaction zone and effecting the conversionof such stream to provide an efiiuent stream containing the desired morevaluable products, effecting the `separation of a light normally gaseousstream from the product stream, separating in addition therefrom atleast one hydrocarbon fraction suitable for further conversion in thepresence of a cata-l lyst to produce a desired improved hydrocarbonstream, passing such lseparated fraction to a hydrogen producingconversion zone andV contacting the same with a catalyst therein atconditions providing a net production of hydrogen and the desiredimproved hydrocarbon stream, separating from the latter stream ahydrogen rich stream and a light normally gaseous stream, passing thehydrogen rich stream to the hydrogen consuming reaction zonev as atleast a portion of the hydrogen being introduced thereto together Withthe charge stream, passing the separated light gaseous streams from boththe hydrogen'consuming and hydrogen producing zones to a secondaryhydrogen producing zone and into contact with sub-divided heatedcatalyst particles, effecting the uidized contact of the latter at anelevated temperature and at a rate effecting the cracking of the lightgaseous streams into hydrogen and carbon, passing at least a portion ofthe resulting hydrogen product stream from the secondary hydrogen Ycomprises thethydrogenation-dealkylation'Yof an aromatic fraction havinga side/chain to `effect theV removal` of at For example, toluene may besubjected to a dealkylationstepbyV pass- .Y produce high yieldsofbenzene.

producing reaction zone into admixture with theV charge stream andY thehydrogen from'the hydrogen producing conversion zone, whereby to supplythe balanceiof hydrogen being passed tothe hydrogen consuming reactionzone as aforesaid. Y

In a preferred combined 'processingV system, embodying hydrogenconsuming and hydrogen producing units it is generally desirable tomaintain a high purityi to .the

Y hydrogen rich stream which VVisrecycled and introduced toV theYhydrogen'c'onsumingunits. `i'l`hus, it is' advisable to continuouslyeffectV the-removal of sulfur and nitrogen g compounds which have beenintroduced into'the system by the various chargeV streams. n a preferredoperation ofthe present system,such contaminantsfare Vremoved from lthesystem bytreating the gaseous and vaporous streams which are introducedinto the iuidized highltern# perature cracking unit. Hydrogen sulfidemay be re- Vmoved, for example, byV conventional means such'asV`Girbotol unit, While ammonia may be removed by Con-.` i

' ventional meansl which may include acidwashmg or the passingof themixture of gases through a cationic ioneXchange resin. 1 z

.In the present description, the term"hydrogen consum-Y ing unit is usedin aV generic aspect to refer to 'any hydrocarbon conversionV processunit which utilizes hydrogen,

thermal cracking, or catalytic cracking,where a high Vboil-VV ingcharge; stream is subject to V `:racking to effect the productionY oflower Yboiling more desirable Vfractions while at the same timeeffecting the cracking of a limitedv amount of the charge to gaseousfractions including a net produc: tion of hydrogen.. Y K .Y Y Y Y, v Y

A dehydrogenation processk also produces hydrogen,

Ysuch as the dehydrogenationof normal propane,fbutane,

pentane, and hexane fractions, or mxturesthereoi to effect high yieldsof oleiinic' hydrocarbons and 'a'netvpro-V ductionV of hydrogen. Theldehydrogenation mayk bel car.'-V riedgout at high temperatures inthelrangefofr 900ur to 1200" P. and at slight superatrnosphericpressures.

Still another hydrogen producing conversion kprocess is the catalyticreforming'of a naphtha or vgasoline boiling range stream to Yproduceimproved octane number'gasoline. Catalytic reforming is now widely usedcommen1 Y cially, beingrcarried Vout in a manner such Yasitairightby`normally in the presence of a catalyst, to aid in `the en-Y hancementof`one or more hydrocarbon charge fractions,

or to effect the conversion of Vone'or more hydrocarbon fractions inrahydrogenating stenta/hereby to provide ariV improved more valuableproduct stream.V Forexample,

hydrogen may berpassed in admixture with a hydrocarbon distillate streaminto contact with ,af suitable refractory hydrocrackingV catalystat hightemperature from about 500 to `about 850 'F. and at'high pressureconditions, j

Vabove 1,000 pounds'per square inch, to effect the selectiver crackingof the distillate stream into desired lower boiling fractions. A mixedhydrocarbon stream maybe subject to rhydrog'enationzto, effectYdesulfurizrationV and nitrogen.

compound removal and kto provide a moresaturated purilied product streamuseful as such/'as fuel or for charge to another conversion unit.Suitable hydrogenation catalysts may comprise sulfur resistantcomposites of a cobalt,

nickel, molybdenum compound or mixtures 'thereofon alumina. Y Y fl Y,

Another process consuming small quantities of hydrogenvmaycomprise theisomerization of butane, pentane,

U.S. Patent VNo. 2,479,140. Hydrogen vproduced from auch units has VbeenusedrinV other processing operations, although not in thesame mannerasjcarriedV outrrby lthe improved integratedprocess of the presentsystem. K E

Stillcther processing operations -Will rbe apparent to those familiarwith'the petroleumV processing artsand it'V is notintended to limitthepresent inventionto the use of theY particular hydrogen producing andhydrogen cou-VV suming operationswhich have been set'forth hereinabove.

However, the presentinV/ention may beV better Vexplained Y and describedand thescope better.understoodrbyfreference to thegaccompanyingdiagrammatic drawing andthe',

following description thereof.' Y

Referring now tothe drawings, there isindicated a ,line Y having valvel2, suitable for passing'aihydrocarbon chargerstrea'm to a hydrogenconsuming Yconversion proc-V ess zone' process maybe effected, generallyin the presence Yola Ycatalytic material. Hydrogen isladmiXedwiththcrcharge and hexane fractions,-or mixtures thereof, where such Y Yractions'are treated in the presence of an isomerization catalyst Yandhydrogenjto Vprovide high yields kofdesired isomerized fractions.Ther'catalyst may compriserplan- Vlnum containingrsolid particles, whileoperating conditions are generally relatively mild,rwith temperatureinthe range Y f offrom about 300 to V900ml?. vand pressure frm-n30() to1000 pounds per square inch. Y

Y Another' hydrogen Vconsuming process ycomprises V*the hydrogenationofY an varomatic stream, such VasV benzene V'to cyclohexane, with highconversionsbeing,obtained by passing the (benzene stream together withhydrogen over a suitable hydrogenating catalyst athydrogenating'condi-Vr tions, and asi'taught forexample in U.S. 'EatentiNo. StillV another hydrogen consumingprocess least one sideV chainVfrom'rsuch stream.

ing toluene fraction togetherwith hydrogen tok a confinedconversionzmeVY maintaining a catalyst, such as Vch'romia'- alumina typecatalyst, at a temperature above aboutY 1200 stream at theconversionzone 3 by means oflinei.l As

y Vhereinbeforeindicated, any one of several types ofrhydro- Vcarbonconversion operations may beV carried out,v how-y zever, for purposes ofillustration itwill be presumed that'. aV gasoil stream is being`subjected toV hydrogenation*iuV zone 3 to effect the Yremoval of sulfurand nitrogen'com pounds, as well asrmetal contaminantgwhereby animaproved fuel oil stream is obtained. VThe`pro'ductfstrearn is passedby wayV of line 5VV to a separationzone 6 4where, `various separationandV fractionation steps vmay bel-'em-V ployed to obtain desiredproductfractions by'wayvoflines' 7 and 8 as well as gaseous fractions.Although-not shown in the drawing, a gas stream comprisingprimarilyhydrogentmaybe Vseparated in a rst'separation stepandused jasrecycle to Vthe conversion-step. ,A normally gaseous Y hydrocarbon andvhydrogen Vcontaining streamfmay be separated andrpasse'd byiwayrofrlmeA91o a sulfur'fand nitrogen compound removalV zonexltl.A VSuch zone` maycomprise conventional'stripping'or absorption means suit;A

as taught in Us.r Par/entita 2,951,835, whereby is Y In a similar aspectthe term hydrogen producing zone is used'generically herein toencompassfone Vor morefhy- Y fdrocarbon ,conversion zones Whichreffect anet Yproduc-V tioncofhydrogen inthe conversion step. Such conversion lstep may comprise, for example, either, high temperature Y able forremoving hydrogen sulfide andammonia from the gaseous stream',Y 5 g rThe resulting treatingstream Y by way of line .l1 Vtoca riserV line 12and-,initio admixture with heated 'catalyst particlesbeingintroduccdlintodinef f2 by way of line VE/Jandcontrol valve 14,ln'accordance, witha preferred embodiment of the Ainvention,therels Y gindicated a'fluidized contactof'the resulting gaseous streamV and theheated sub-divided catalyst.particles. k There isfafu Y continuousintroduction ofthe stream and entrained par. Y ticles into anyeleyatedVreaction 'zone Vl5 YmaintainingfaV1 iiuidized oragitated dense phasebed'of catalyst-16,5"VIV-heYV catalyst particles are introduced intoadmiXturewith the; hydrocarbon stream at the Vlower end ofriserlirielZlat al temperature of about 1200K`Fzto aboutl600Y F, tofornfl Y a resultingYY cracked product stream Acomprising piinarily` Q Yhydrogenrwith little or no formation of 'carbon oxides 'A;

'small amountfof unconvertedmethane comprises the prin;

`Such zone is, of course,'n'ot shown in detail and may comprise one'ormore reactors, heaters, and afc-H companying apparatus whereby aparticular. conversioni from zonelt is passed cipal, contaminant in thehydrogen stream passing. overhead from the reaction zone by way of line1'7 and compressor 18.

In the preferred embodiment using a tluidized operation, contactedcarbonized catalyst particles from the tiuidized bed 16 are continuouslypassed by line 19 and control valve 20 to a regenerator or carbonburning zone Z1. In the latter, carbon is continuously removed fromcatalyst particles by burning in the presence of air or other oxygencontaining stream being introduced by line 22 and valve 23 into thelower portion of regenerator 21. The oxygen content ofthe streamcontacting the particles in the uidized bed 24 is controlled to effectthe burning of that amount of carbon that is continuously deposited onthe particles and to etlecta temperature suicient to reheat theparticles to in turn supply the endothermic heat of conversion in thereaction z-one. Thus, the catalyst particles may be reheated to atemperature in the range of l300 to 1806" F., whereby to effect theresulting high temperature cracking of the hydrocarbon stream tohydrogen and carbon. A controlled oxygen content and acontrolled carbonlevel are also maintained in the regenerator 21 in order to provide thedegree of carbon omdation required to fulll the thermal demands of theprocess.

Under most conditions the ue gas contains large percentages of carbonmonoxide. A resulting carbon monoxide rich stream is discharged from theupper portion of the regenerator by way of line 25 and. control valve 26to a carbon monoxide consuming zone 27; The latter may comprise a carbonmonoxide burner or boiler suitable for producing a quantity of hightemperature steam, or alternatively, as hereinbefore set forth, thecarbon monoxide may be utilized as a reducing stream for anotherprocessing operation, or provide a source of carbon monoxide in theproduction of urea, formic acid, and the, like. The present drawingindicates a ue gas stream being discharged from the zone 27 by way of'line 28 and valve 29 and water introduction through line 55 and valve,57i, with steam discharged by Way of line 58 and valve 59. An auxiliaryline 39 with valve 31 is available for recycling aY carbondioxide richstream to the air line 22:` tand providing thereby a control of oxygencontent to( the regenerator. The admixture of carbon dioxide furtherserves. to enhance the equilibrium production of greater quantities ofcarbon monoxide during the regeneration or carbon burning step.

At the lower end of the regenerator zone 21 means is provided forstripping the heated sub-divided catalyst particles prior to theirintroduction to the cracking zone 15. Nitrogen or other inert gaseousmedium is charged through line 32 and valve 33 to the stripping zone 34so as to effect a concurrentcontact of the catalyst particles as theydescend from the lower portion of bed 24 to the outlet line 13. It hasbeen found that the removal and stripping of carbon oxides and any metalcontaminants which may become entrained with the particles from theburning zone, need to be removed prior to the introduction of the heatedparticles` to the cracking zone so as to prevent any reducing operationtaking place in the crack ing zone andl to in turn provide optimumyields of hydrogen with a minimum of carbon oxides as a contaminant tothe hydrogen stream. The drawing indicates a cocurrent vapor stream andparticle flow into and within the reactor 15, however, countercurrent owof vapors andV subdivided particles may well be carried out in theconversion zone within the scope of the present invention.

In the combined operation the hydrogen rich stream leaving the crackingreactor 15v is passedby way of compressor 18 and line 4 with valve 35 tothe hydrogen consuming zone 3 whereby to provide at least a portion ofthe necessary hydrogen for such conversion zone. In the present combinedsystem, it is alsoV to be noted that the hydrogen producing reactor 15may serve as a secondary source of hydrogen, the primary source beingprovided by a hydrogen producingzone 36 receiving a hydrod carbon chargestream by way of line 3 7 and valve 38. The charge through line 37 maycomprise a hydrocarbon stream obtained from an outside source or it maycomprise a product stream obtained from the separation zone 6 followingthe hydrogen consuming process step taking place in zone 3, such productstream being passed by way of line S and valve 39 to line 37. Forexample, zone 3 may be used for the hydrogen treating of a naphthaV orgasoline boiling range stream which is to be subjected to catalyticreforming within the hydrogen producing zone 36. On the other hand, ashereinbefore indicated, one or more hydrocarbon fractions which are tobe subjectedV to dehydrogenation, or a high boiling fraction which is tobe subjected to cracking, may be introduced as charge through line 37 tozone 36. The latter zone may comprise one or more reactors andaccompanying heaters, pumps, exchangers, etc., suitable to eiect adesired conversion and discharge an effluent stream of improved morevaluable hydrocarbon fractions. Such stream is indicated as passing byway of line 40 to separation zone 41 wherein there is effected thenecessary separation land fractionation of the eiiluent stream toprovide at least one or more product streams at lines 42 and 43. Thereis also separated in the present embodiment a hydrogen rich stream byway of line 44 having valve 45 and a normally gaseous fraction, whichmay contain some entrained hydrogen, being discharged by way of line 46.

Although not indicated in the drawing, a portion of the hydrogen streamfrom line 44 may be continuously recycled to the hydrogen producing zone36 to provide a hydrogen environment for the conversion step, however,the net production of the hydrogen rich stream is passed by way of line44 and valve 45 into admixture with hydrogen passing by Way of line 4and to the hydrogen consuming process zone 3. Depending upon the typesof conversion being effected in the respective hydrogen producing zone36 and hydrogen consuming zone 3, there may be either a large or smallquantity of hydrogen produced for use in zone 3 and there may be varyinghydrogen demands within the hydrogen consuming zone 3. In an alternativearrangement the net hydrogen pro.- duction in line 44 may be passed byway of line 47 and Valve 48v to line 46 which is provided to carry ,alight hydrocarbon stream to the treating zone 10 and. to the hydrogenproducing reactor 15. This arrangement serves to utilize the hightemperature cracking zone 15 as a hydrogen purier. In other words, thehydrogen content of the stream is enhanced by the conversion of thelight hydrocarbon components from line 46 to hydrogen and whereby aresulting stream may be obtained from the reactor 15'A having a 85%hydrogen content or more. Sulfur and nitrogen compounds are removed intreating zone 10 prior to the stream being passed into contact withcatalyst particles at the lower end of riser line 12. Such treating stepprecludes the building up of contaminating materials in the treatingsystem.

In another alternative operation the combined system may make use of aproduct stream from the hydrogen producing zone 36 as a charge to thehydrogen consum- Ving process zone 3. For example, an aromatic fraction,

such as benzene or toluene, may be passedby way of line 43 and valve 49to join with line 1 as the charge to the hydrogen consuming zone 3,whereby such aromatic fraction may be subject to hydrogenation to form acyclo,- paraftin, or alternatively, be subjected to dealkylation toremove a side chain therefrom.

As previously indicated, the present drawing is diagrammatic and doesnot show all pumps, valves, separating and fractionating equipment andthe like which may be advisable or necessary in the design of acommercial unit. The hydrogen consuming and hydrogen producingVconversion operations may be carried out in batch operations, butpreferably are effected in a continuous manner by the use of suitablereaction zones which in turn make use of 'rand fixed or iluidiaed bedsof catalyst.V Where necessary, suitable regeneration provisions maybeprovidedto eifect continuous or periodic reactivation of catalyst bedswhich linay be used Yin-suchunits. In connection with the fluidizedsecondary hydrogen producing zone, particle separatinnieans is shown-diauramrnaticall atthe upper ends t D D Y V'line' 46 to the Secondaryhydrogen producingtronc.V A

' resulting improved octane number gasoline isrdischarged ,oftheVContact' chambers. VA particle separator 'SG being Y.

indicated at the topof reactorl'e is suitable' for removing andreturning entrained catalyst particles to the lower por@ tion of theconversion Vzone andV to'catalyst bed lfd,V and particle separator lservesY to return'entrained catalystk ,particles tothe bed 2li inthelower portion of regenerator In aV combined operation havinghighhydrogen requiremontait may be necessary Yto provide an auxiliary chargeY,

of methane, or other hydrocarbon stream, to the iiuidize'd hydrogenproducing zone l5, such charge being introduced by Vway or -line 52 andvalve 537m therlower end Yof'riser line l2, whereby high temperaturecracking will effect the production of an increased amount of hydrogen.On .the

. gen andrcarbonl at the cracking reactor l5. .*A'resultinghighhydrogenV contentstr'eamlfrom line 17 andcompres#y other hand where thecombined integrated system has a Ynet production fof hydrogen over andVabove that needed in the system, then excess hydrogen may be withdrawnfrom line i by way oi line S4 and valve 55. Such hydro- V genV being,.as hereinbeiore noted, of substantial high hyzdrogen puritycontaminated only witha small amount of methane and a very minorquantity of Vcarbon oxides;

' where` desirable, the srnallV amount of carbon oxides may be,A in turneliminated by passing the'product stream to a methanation Zone andefecting the conversion ofvcarbon monoxide and carbon dioxide to methaneby the following reactions; i Y Y Y v YTo illustratefurther utility ofthe'present improved corn` to the Ycracking zone l5.

by way of yline 4Z from separation zone 41. Atthe Vsecondary hydrogenproducing unit, the light gaseous fractions which may contain someVentrained or absorbed hydrogen, enter riser line Il?, from lines 9 and46 andltherein contact heated catalystat a temperature of'from 1200 to1650"Y F. and at a rate eectingrthe formation of hydrorsor i3 isV passedto line 4to combine withy hydrogen produced from zone and passed by wayofline'ij VWhere excess hydrogen is available, it is Ywithdrawn fromline4 by way of line 54. Y l Y 'Y The removal of carbon andthe reheatingofthe catalyst particles in the secondary hydrogen producing zoneis car#rie'd out as Vhereinbefore described 'inconnectioni with the rawing,catalyst particles passing by way of line 19in regenerating .zone 2l andreheated activated catalyst par'- ticles passed from stripper 34 to line13 for recirculation ExampleV ll Y A naphtha stream is introduced byYway of line and valve 38 to hydrogen producing zone 3d and thereincontacts a reforming :catalyst atY reforming conditions to'pro-V f videan improved octane number product stream Vthat'is bined system thefollowing examples `set Vforth varyingYV integrated combinations ofconversion processes: i Y

VK Y Example l Y Y A gasoline boiling range material is charged to the Yg hydrogen consuming zone 3 to effect the removal of sulfur,

nitrogen and metal contaminants and to provide aj suitable gasolinecharge streamfor a reforming operation in zone 36.VV Thus, the chargeiscontacted in zone 3 at ,a ternpera.

,ture in the Vrange from about"500 to Y80G F. and at a pressure intherange of from about 2 00 to l50 pounds per squareinch over a sulfurresistant catalyst andV in the presence of hy rogen' to effectsaturation and desulfuriza K tion,V et'cf, ofA the charge. Catalystssuitable Vtor'suchV hy- Vdrogenation operation are Vwell known Vin, theindustry,Y

usually comprising one. or Vmore oxides of cobalt,.-molyb Y denum andnichel, onf a suitable supporting material.Y The efiluent productYstream is separated at zone 6 to provide fa naphtha orV gasolineboiling range stream for reforming Y that issin' turn passed rby wayroflines 8 and 37 to the,l

hydrogen producing process zone 36. Such stream is con-V Y 'vertedtherein inthe presence of hydrogen and in the pres` Y ence of a'suitablereformingcatalyst at a temperature of Y "7009 to 100051?. and at apressure of 200 to 1,000 poundsV Vper. square Vinch to produceran octaneVnumber gasoline stream. Likewise, the catalysts for reforming are .well

'known' in `the industry and'may comprise` platinum, palla-YV diurn,or'other noble metal, on a suitable supportY such as Y alumina, togetherwith an acid component, such as hdogen cCJi rich in aromatics. Asdescribed ,in connection with the drawing and l-EX'arnplev I, a hydrogenrich stream is'separated and discharged by way of line 46 to'lineA andthe hydrogen consuming Vzone V3 while a light hydrocarbon i gaseousfraction isseparated and pasd by-waylof line 46 to Ythe :treating zoneit? and jto the cracking reactor V15 for the production-of additionalhydrogen; Theliquid product strearndischarged from line l0 maybeseparated. in a'manner to provide Vthe removal of aromatic fractions,as, for example, by the use'ofa solvent extraction Yprocess thatprovides benzene, toluene, and Xylene frac"-V tions. At least a portionof the benzene fraction fis thenY` withdrawn and passed byv way of line43 to providecharge to the hydrogen consuming. process 3. In -thiszone'th'e benzene, fraction is Vsubjected Vto VVhydrpgenation Y in, the

`presence of a suitable hydrogenation catalyst, :suchasa Vnickelcompound composited on a siliceous support/and i in the presence ofhydrogen being introduced by'lline'4,

whereby the resulting hydrogenation'- provides a khigh yield o fcyclohexane. VThe cyclohexaiier rich .effluentV stream 1s passed by wayofline 5k to Vseparation zone 6 where it is subjected toV suitableVseparationV and fractiona.

tion to provide a desired cyclohexane rich productstream g at line 7,and at least alight gaseous fraction, Which'may A containV somehydrogen. YThe latter is passed'by'wayof Y Vline 9 totreating zonel'and'to the'secondaryrhyd'rogenV producing zone forfurtherahydrogenproduction, or Lto` effect puriication, whereby there is anenhancementof hydrogen content to the streams Vbeing introduced to 're-Vactor 15 by way offboth lines 46 and 9,7.V Tlif'fwresultingY hydrogenVrich streamjrom reactor 15 passes by way; lof,V

line V17, compressor 18 and Vline tto combine with the lized inthehydrogen consuming zone 3.YAY

Y Y tsjmmplt` lil'A Y Y Y In an alternative to the operation'set forthin YExample jhydrogen from line 44 and in turn provide hydrogen ut-ivIl, a toluenerich stream is Withdrawn from-separation or silica. Onesuch catalyst being the YPlatforrning'catal f lyst now widely usedinconnectio'n'with,thefPlatforrning reformingprocess.y The eiiuentstream from'conversion f zone 36 Vis subjected to separation andfractionation at zone Vil so as to provide a hydrogen richY stream,which VmaycornpriseY or more, of hydrogen being'dis- Vcharged by Wayrofline 4- to line 4 to'in Vturn provide at least arportion of the hydrogenfor the hydrogenation step Yinuzone 3. lA light normally gaseoushydrocarbon fraction lis'also separated at zone {tl/andisdischarged byWay ofV 'rich Iinbenzeue.'V VThe desiredrbenzene stream may be withdrawnlfrom separation Yzone 6 vrway offline 7l, 'l

. zone 'fil andlpassed' by Way of line 43'toV the hydrogen Vconsumingprocess zone 3. VThe `toluene stream being `therein subjected toVContact with VVAa suitable nhydroYV .dealkyla-tion catalyst, suchas,.-for example, Vclztromiaon alumina, at'a temperature aboveabout12005R e n VThe charge stream in zoneV also contacts the ,catalyst 1nthe presence -of hydrogen from line Aat Va, pressure of j from to 1000pounds per square inch, etfectingr-tlw1e'V Vremoval Vof an -alkylradicalto provide an elrluent'ustrearn While in a manner similar to theoperations hereinbefore described, a lower boiling hydrocarbon fractionis separated and passed by way of line 9 to the treating zone andcracking reactor 15 for the production of an improved high hydrogencontent efuent stream at lines 17 and 4. Excess hydrogen may bewithdrawn from the system through line 54.

Example IV As set forth in Example 1I, a naphtha stream is introduced byway of line 37 to the hydrogen producing zone 36 wherein there isetected the reforming of such stream in the presence of a reformingcatalyst at reforming conditions'to provide -an improved octane numbergasoline stream. The product stream is separated in zone 41 to providean overhead hydrogen rich stream and normally gaseous hydrocarbon streamin the manner also set forth in Example II, while further separation iseffected to obtain normal C4, C5, and C5 fract-ions. One or more of thefractions, or a mixture of such fractions, are passed by way of line 43to the hydrogen consuming conversion zone 3 wherein there is effectedthe isomerization of the charge stream in the presence of anisomerizating catalyst. The isomerization catalyst in zone 3 may, forexample, comprise a platinum compound or a solid support material suchas alumina. The stream to be treated contacts the catalyst at atemperature of from about 300 to about 900 F. and at a pressure of fromabout 300 to about 1,000 pounds per square inch, in the presence ofhydrogen introduced from line 4.

A resulting isomerized product stream may be withdrawn from separationzone 6 by way of line 7, while a separated normally gaseous hydrocarbonfraction is passed overhead by way of line 9 -to the treating zone 10and to the secondary hydrogen producing reactor in accordance with theprocedure described in the foregoing examples. In the present operationthere is only a small consumption of hydrogen in the conversion zone 3and as a result there is more hydrogen produced from the reformingseparation zone 41 and from the h-igh temperature cracking zone 15 thanis necessary for use in the combined system. Thus, net hydrogen with asubstantially high purity may be withdrawn from the combined system byway of line 54 and valve 55.

Example V A hydrocarbon distillate stream, which may comprise a wideboiling range material with an I.B.P. of about 400 and a 900 F. El. ischarged by way of line 1 tothe hydrogen consuming unit 3. It is thereinsubjected to selective hydrocracking in the presence of hydrogen,introduced by way of line 4, and a hydrocracking catalyst contact at atemperature in the range of about 500 to about 850 F. and asuperatmospheric pressure above about 1000 pounds per square inch. Thecatalyst may comprise a refractory support such as silica-alumina withan activating component comprising one or more oxides of the iron groupof metals of Group VIII of the Periodic Table. In separation zone 6 theresulting hydrocracked eduent stream may be separated to provide lowerboi-ling fractions including C3, C4, and C5 components suitable fordehydrogenation in the hydrogen producing zone 36. A light gaseousoverhead fraction is separated and passed by way of line 9 to treatingzone 10 and then by way of lines 11 and 12 to the secondary hydrogenproducing cracking reactor 15 whereby to effect the conversion ofhydrocarbon fractions contained therein to hydrogen and carbon. Hydrogenso produced is passed by way of lines 17 and 4 to the hydrogen consumingzone 3 to thus supply the necessary hydrogen for the hydrocrackingconversion step.

One or more of the C3 to C5 fractions is passed by way of lines 8 and 37to the conversion zone 3d wherein such fractions are subject todehydrogenation in the presence of a dehydrogenating catalyst maintainedat dehydrogenating conditions. The dehydrogenating catalyst in zone36m-ay comprise, for example, a chromia-alumina catalyst and thehydrocarbon stream is passed at a temperature of from about 1000 to 1200F. and at a slight superatmospheric pressure into contact with suchcatalyst. Resulting unsaturated products are passed to the separationVzone 41 and there-in subject-to separationy and fractionation toprovide one or more product streams, as Well as an overhead hydrogenstream passing by way ofline 44 to line 4, and a normally gaseoushydrocarbon fraction passing by way of line 46 to treating zone 10 and`to the high temperature cracking reactor 15. Again, where excesshydrogen is provided by the system, suchexcess may be withdrawn by wayof line 54.

Example VI A hydrocarbon distillate stream, which again may comprise awide range boiling material, is treated 'in the hydrogen consuming zone3 to effect the hydrocracking thereof in the manner set forth in theforegoing Example V. At the same time a gas-oil stream, which may or maynot be obtained from the separation zone 6, is introduced to thehydrogen producing zone 36 wherein there is. effected a catalyticcracking of such gas-oil 'fraction to produce a marketable gasolineboiling range material. The gas-oil cracking may be substantiallyconventional, contacting a silica-alumina catalyst at a temperature offrom about 800 to about 1000 F. and at a suitable rate of contact toprovide desired high yields of gasoline boiling range material. Thecontact may be effected at low superatmospheric pressure in a fixed bedor in a luidized. catalyst operation. Both types of operation are widelyused in the industry and it is not intended to limit the presentcombined process to any one type of contacting `operation in this step.Separation is eifected to provide one or more liquid product streamsfrom zone 41, as well as to separate a normally gaseous fraction whichis passed overhead by way of line 46 to treating zone 10 and the hightemperature cracking reactor 15, whereby hydrocarbon components in thestream may be converted to hydrogen and carbon in the manner heretoforeset forth in the previous examples. A resulting hydrogen rich stream ispassedfby way of lines 17 and 4 to the hydrocracking conversionoperation in zone 3. In connection with a cracking operation as setforth in this example, it is generally preferable to separate a singlelight gaseous hydrocarbon fraction to pass by way of line 46 to thesecondary hydrogen producing zone.

Example VII A light or reduced crude charge is passed by Way of line 37to the conversion zone 36 and there-in subjected to thermal cracking atan elevated temperature of from about 800 to about 1100 F. and asuperatmospheric pressure above about 200 pounds per square inch. Theresulting cracked fraction is separated in zone 41 to provide desiredlower boiling liquid products as Well as an overhead gaseous fractionpassed by way of line 46 to treat ing zone 10 and the high temperaturecracking reactor 15, whereby to effect the production of a hydrogen richstream. A gasoline or naphtha fraction is obtained from separation zone41 and is passed by way of line 43 to the hydrogen consuming zone 3 andis therein subjected to hydrogenation by contacting a suitablehydrogenating catalyst at hydrogenating conditions, such as set forth inExample I. There is thus provided a resulting puried and desulfurizednaphtha product stream suitable for use as such, or as charge to acatalytic reforming unit t-o produce a high octane gasoline. An overheadgaseous fraction is discharged from separation zone 6 by way of line 9and passed to the treating zone 10 and the hydrogen producing zone 15whereby resulting hydrogen is provided for use in the -hydrogenationzone 3 by Way of line 4. In this particular combined process a hydrogenrich stream may be separated following the cracking carried out in zone36, however, a preferred operation will generally separate Y system willbe apparent to those familiar with Vedmv processing arts.

Vll

a single gaseous fraction from Vzone i` to pass by way Y of line 46 intoadmixture with the gaseons fraction'from We'claim as our invention: f 1.A conversion process Vwhich comprises Y (l) subjecting hydrocarbon oilinadmixture with hyaneeee i [drogen to a hydrogen-consuming reaction in afirst conversion zone, Y (2) separating from theresultant productsanormally gaseous hydrocarbon'fraction yand arnormally liquidhydrocarbon fraction, (3) cracking said normally tact withk heatedsubdivided,catalystrparticles, Y Y Y (4) subjecting said normally liquidraction'to a hy- Y drogen-producing conversion reaction in a third conlversion zone,

i (5) separating a hydrogen-containing gas from the! ellluent ofsaid'third zone, and Y (6) introducing atleast a portion of said YgastoV said second zone and .passing hydrogen from the latter to gaseousfraction to hydro-V Y gen and carbon in a second conversion zonein con-Y said lirst zone to Vsupply-hydrogen for `the hydrogen- Y consumingreaction therein. Y V2,'The process'of'claim il further characterized asaturationy and desulfurization-of a gasoline fraction is eiected insaid iirst zone and in that a reforming of thus treated gasolinehydrocarbonsis effected in said third zone. Y Y

3. Arconversion process which comprises ,i

in that Y Y (l) subjecting'hydrocarbon' oil in admixture withhydrogen toarhydrogen-consuming reaction in Ya'tirst conversion zone, t Y n g Y (2)separating from the resultant products a normally gaseous hydrocarbonfraction and a normally liquid Y hydrocarbon traction,y Y f (3)subjecting said normally liquid `fraction to a hydrogen-producingconversion-reaction in a third Yconver- V sion z one, Y f Y Y(4),'separating from the efiluent of ,said third Vzone a vaporousstream' containing hydrogenV and `Ylight hydrocarbons, Y Y f Y Y (5)contacting said vaporous streamand said normally gaseous hydrocarbonfraction with subdivided heated catalyst particles at a temperaturesulicient to Vcrack the major portion, of the hydrocarbons contained Ytherein to hydrogen and, carbon, and

V(6) introducing `hydrogenthus formed to said rrst zone to supplyatleast arrportion ofY the hydrogen Y for the hydrogen-consuming reactiontherein,V

References Cited by the Examiner UNITED STATES PATENTS Y Rex 208-136ALPHONSO D. SULLIVANY prima@ Emm'ne'r.V

1. A CONVERSION PROCESS WHICH COMPRISES (1) SUBJECTING HYDROCARBON OILIN ADMIXTURE WITH HYDROGEN TO A HYDROGEN-CONSUMING REACTION IN A FIRSTCONVERSION ZONE, (2) SEPARATING FROM THE RESULTANT PRODUCTS A NORMALLYGASEOUS HYDROCARBON FRACTION AND A NORMALLY LIQUID HYDROCARBON FRACTION,(3) CRACKING SAID NORMALLY GASEOUS FRACTION TO HYDROGEN AND CARBON IN ASECOND CONVERSION ZONE IN CONTACT WITH HEATED SUBDIVIDED CATALYSTPARTICLES,